DRILLMATE DRL GUIDE 16" *Brand Name: Milescraft *Sub Brand: DrillMate *Style: Portable *Product Type: Drill Guide *Number in Package: 1 pk *Packaging Type: Clamshell *Usage: Works with most 3/8 in. drill accessories. NOT INTENDED FOR USE WITH IMPACT DRIVERS OR HAMMER DRILLS *Maximum Drill Bit Clearance: 7.5 in. *Base Opening Diameter: 3-1/2 in. *Minimum Drill Bit Clearance: 0.72 in.